问题 问答题 简答题

钢材的主要化学成分是什么?钢材中的微量元素包括什么?

答案

参考答案:

钢材主要化学成分是铁,在普通的碳素钢中约占99%;

钢材中的微量元素有①碳(C);②有利元素锰(Mn)、硅(Si);③有害杂质元素硫(S)、磷(P)、氧(O)、氮(N)、氢(H);④在合金钢中还有特意添加以改善钢材性能的某些合金元素,如锰(Mn)、钒(V)等。

阅读理解

任务型阅读,将划线部分的句子翻译成汉语或英语。

     http://kidshealth.org/teen/school_jobs/school/testing_tips.html

     Do you get nervous as your teacher hands out the test papers? If so, you are not alone. (1). A lot of

people become very nervous when it's time to take a test. It's natural to feel some stress about taking

tests. Here are some tips for taking tests.

    Be sure you've studied well. That will help you feel sure about your answers in the test. (2). 考试之前睡眠要充足。 Your memory will be much better if you've had enough rest. In a scientific study, people

who got enough sleep before taking a math test did better than those who stayed up all night studying.

     Listen closely to any instructions. As the teacher hands out the test, be sure you know what you

should do during the test. Read the test through first. If something seems not clear before you start, just

ask your teacher. As you take the test, if you don't know an answer, don't be obsessed (被困扰) by it.

 (3). Instead, let the question alone and come back to it after you've answered other questions.

     Finished already? Maybe the teacher will let you hand in your paper early. (4). But it's usually a good

idea to spend any extra time checking over your work.

     These tips should help most people, but some can get serious test-taking fear. (5). 如果你是其中的一位,你或许需要和你的父母或老师谈一下,以寻求帮助

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4. ___________________________________________________

5. ___________________________________________________

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